Howard Stern recently inked a new $400 million contract, but the self-proclaimed “King of All Media” is getting the royal shaft from Sirius XM Radio, a new lawsuit claims.

Stern’s production company, One Twelve, and longtime agent say in a Manhattan suit that the satellite-radio company has been stiffing them out of big-bucks stock awards for the past three years — even though they’ve exceeded subscriber goals.

“Now that Stern has put the company on the map,” Sirius has “decided that Stern has been paid enough,” the suit gripes.

Stern, who just finished a $500 million, five-year contract, has re-upped for another five years for a reported $400 million.

In a statement, Sirius called Stern “a valued part of our company,” adding it is “thus surprised and disappointed by this subsequent legal action.”